1. Field of the Invention
This invention relates to a water feeder for use mainly in the poultry industry.
2. Description of the Prior Art
The water feeder systems used in poultry houses consist of a water supply pipe fitted with water feeders each having a feeder pin at its lower end. When a chicken lifts the tip of the feeder pin with its beak it is automatically supplied with water.
Water feeders of this type are taught, for example, by Japanese Utility Model Public Disclosures Sho 59 (1984)--29179 and Hei 3 (1991)--9150 and U.S. Pat. Nos. 3,669,077 and 4,524,724.
The water feeder according to U.S. Pat. No. 4,524,724 is shown by way of example in FIG. 7 of the attached drawings. The water feeder comprises a cylindrical housing 30 attached to a water supply pipe (not shown) and a plug 32 with an internal vertically movable feeder pin 31 is fitted into the lower opening of the housing 30. Inside the housing 30, a spherical valve 33 is pressed onto the top of the plug 32 by a small amount of water pressure and its own weight, thus sealing the upper opening of the plug 32 and closing off the supply of water.
When a chicken raises the feeder pin 31 with its beak, the spherical valve 33 is raised to form a gap between the valve 33 and the edge of the upper opening of the plug 32. As a result, the low pressure water in the water supply pipe passes through the housing 30 and the plug 32 so that a drop of water forms on and falls from the pin 31.
Although chicks require only a small amount of water at first, the amount they need increases gradually as they get larger. If the amount of water supply should become insufficient, the growth of a chick can be markedly stunted.
With the prior art water feeders, since the practice has been to adjust the amount of water supplied to that appropriate for the chicks, such amount of water is insufficient for the fowl to prevent the fowl from fully growing. When the amount of water is adjusted for the fowl, however, there is a possibility of the chicks scattering excess water around the poultry house and, as a result, the floor of the poultry house gets wet. This promotes the propagation of bacteria and mold and thus increases the risk of the fowl contracting diseases. The amount of water supplied can be adjusted to some extent by regulating the water pressure, but this water supply adjustment has its own limitation.
The problem with this is that the water spilled on the floor and remaining on the feeder pin 31 is scattered around the poultry house by the birds as they move about. Since this wetting of the interior of the poultry house promotes the propagation of bacteria and mold, it increases the risk of the fowl contracting diseases.
In addition, the feeder pin 31 of the prior art water feeder makes line or surface contact with the passage wall 32a of the plug 32 and tends to stick to the passage wall 32a owing to the viscosity produced by chemicals added to the water. When this happens, the water feeder stops acting as a valve for the supplied water and allows water to flow uncontrolled, leading to further wetting of the poultry house floor. In addition, the feeder pin 31 sticks to the passage wall 32a owing to the surface tension of the adhering water, making it difficult to push the feeder pin 31 upward.